43 replies to this topic

[okto]

has anyone toyed with fitting a device to reduce the muzzle noise of any of their nerf weapons? clearly we arent dealing with the explosively hot and superheated gases of a firearm, so different rules apply. would a length of pipe insulation fitted post-muzzle help, or would a larger diameter PVC pipe with some sort of baffle and bleed ports work better? mostly im throwing this out to spark discussion, although im interested in other people's ideas as my LnL wants to be a lot quieter to excel at being a loser pistol.

[taita cakes]

DISCLAIMER: Silencers are illegal.

I don't quite know the termonology, but i think the baffle and bleed ports are what work. I think it was Zero, or someone being flamed by Zero, that designed a concept where you add an extra few inches onto the barrel, that has points drilled through it, and the entire barrel extension is wrapped in foam insulation so that the air slowly bleeds out. Hmmmm, bleed ports, so i was right.



i will mention again these are illegal

[Ice Nine]

Do some research next time. All you had to do was look at this friggin' site.

[Crankymonky]

Let me clarify something. It is illegal to have a silencer on a firearm, and a stock on a full auto firearm. NERF GUNS ARE NOT FIREARMS, unless they penetrate skin. If they were firearms the RF20 would be illegal, due to a stock type thing. Unless someone can get me a superior legal definition of a firearm, I am sure nerfguns are not firearms.

If nerf guns were firearms you sure wouldn't be able to buy them under a certain age (depending on location)
A gun, pistol, or any weapon from a shot is discharged by the
force of an explosive substance, as gunpowder.
I don't know of a nerf gun using explosions, except maybe that baking soda +vinegar one.

Edited by crankymonky, 05 July 2004 - 09:22 AM.

[xedice]

I think it was cxwq that clarified this, silencers aren't illegal because of nerf, its because they can be put onto a real firearm.

Just make your silencer anyway, cops aren't going to care. Besides, a silencer for a spring gun won't reduce the noise by even a decibel because the noise is made from the piston hitting the case, not air popping out. silencers for nerf = useless

What was that movie where a guy with a gun shot a clerk and used a 2 liter coke bottle to silence it. Are coke bottles illegal to carry around now? Mind you, a 2 liter would silence a firearm just as much as a homemade silencer would silence a nerf gun.

Edited by xedice, 05 July 2004 - 10:49 AM.

[okto]

ive already silenced the piston. circles of neoprene mousepad, stacked several layers thick, glued to the face of the piston. also a strip of backer rod in the channel of the cocking lever and backer rod round the outside of the cylinder.
reduces noise slightly and eliminates rining, but most of my firing noise is still the 'thwop' of the compressed air behind the dart expanding rapidly out of the muzzle.

my first barrel was ported, and had a PVC sleeve around it that was ported as well in an attempt to bleed the air off, but it didnt do a whole lot.
that barrel was 1" long screwed into the stock LnL barrel to fit the OD of micros, so it clearly had other issues. it was a first mod and an attempt to keep the pneumatics as close to their original condition as possible. ive since taken a hacksaw to them.

ice nine, calm. im not a n00b, just new to this particular board. don't worry.
but thank you for the link.

Edited by okto, 05 July 2004 - 01:22 PM.

[taita cakes]

Heh, i knew i'd get flamed for that.
I hopped into bed that night, and thought "FARK, detachable sileners are illegal "

I like your concept of silencing the internals, sounds good.
Good luck, hope i helped.

[Zero Talent]

taita_cakes, on Jul 5 2004, 02:13 AM, said:

...I think it was Zero, or someone being flamed by Zero, that designed a concept where you add an extra few inches onto the barrel, that has points drilled through it, and the entire barrel extension is wrapped in foam insulation so that the air slowly bleeds out. Hmmmm, bleed ports, so i was right.

Did I flame a guy for porting his barrel? I don't remember doing that... I rarely flame designs, I usually just construct criticism and add suggestions.

Best way to ensure that friction is not increased by the ported holes (since many darts are placed in barrels under a bit of compression) is to use a slightly larger size of piping for the ported part, either with the SDR-11 version of your PVC, a size up in brass, or just by enlarging the inner barrel with a slightly larger drill bit or with a dremel. Sure, it's not as effective, but I just wouldn't trust drilled holes with the side of closed-cell foam too well. Frayed, you know?

[Just to toss on again, sorry if I come off as insulting when I criticize ideas; that's not the intention at all.]

Edited by Zero Talent, 05 July 2004 - 11:42 PM.

[taita cakes]

Certainly not. It's just, in termonology, theres a fine line between flaming and constructive criticism. You're too much of a contributor and homemade god, why would we not take it from you?!

Anyway, i suggest the earlier method. I couldn't remember whether it was you, Zero, who created it, or more memorably, you, who prove the theory wrong.

Basic Physics would say that design works very well...

[okto]

been playing with spiral ported CPVC surrounded by closed-cell pipe insulation, and no reduction in noise. the thought struck me that hey, closed-cell is the same thing darts are made of, so why would thye hold air as darts and then leak is as silencer baffling? (along this same line of thought i made a 'rifle grenade' type dart out of the insulation. goes about ten feet at low velocity, so its a gimmick)
so i tried removing the closed-cell and wrapped a sock around the riddled-with-holes CPVC and fired a couple test shots. slight reduction in noise, but not significant :/
so it comes down to finding a good baffling material, i think. logically it has to work: noise caused by rapid expansion of compressed air out the muzzle can be reduced by contained dissipation and deceleration of said air.

[taita cakes]

okto said

so it comes down to finding a good baffling material, i think. logically it has to work: noise caused by rapid expansion of compressed air out the muzzle can be reduced by contained dissipation and deceleration of said air.

Budda-Bing. Have a dollar.

[NinjZ]

Keep in mind, the silencers only really work on the pump guns. They make a loud "pop" or "fut" sound from air and the dart expelling from the barrel.

[taita cakes]

Well, he's already silenced the internals as much as he can.

Maybe he should try hundreds of minute holes with the smallest drill bit he's got, and then not wrap it with foam insulation/layers.

[Worlds largest bed race]

All I do is put a slightly larger size of 1/2 brass to 1/2 cpvc with a 1/2 inch pvc couplink(SP?) and this reduces the noise.But it's alot easier to scilence a spring-cock gun.All you have to do is push the FBR dart back into the barrel as close to the place where the plunger tube ends and the plunger hits as you can with out pushing the dart into the tube itself.This will give the air no where to go and allow more time for air pressure to build up and slightly slow down the plunger so it doesn't bash aginst the front of the plunger tube.Now sometimes if the FBR is to tight it will throw off the accuracy because the increased friction of the tight dart will put a spin on the dart,all you have to do is put a brass barrel extender(mentioned above) on and that will correct the any spin put on the dart.

[polarthunder]

As stated by the ATF (Bureau of Alcohol, Tobacco, and Firearms):
(A9) Q. Are Paintball and/or Airgun Sound Suppressers legal? [Back]

A. §921(a)(24) The terms "firearm silencer" and "firearm muffler" mean any device for silencing, muffling, or diminishing the report of a portable firearm, including any combination of parts, designed or redesigned, and intended for use in assembling or fabricating a firearm silencer or firearm muffler, and any part intended only for use in such assembly or fabrication.

Numerous paintball silencers tested by the Firearms Technology Branch have been determined to be, by nature of their design and function, firearm silencers as defined in 18 U.S.C., Section 921(a)(24). An individual wishing to manufacturer a firearm silencer must receive prior approval from ATF by submitting an ATF Form 1 and paying a $200 making tax.

Now all you have to do is figure out whether or not a Nerf gun is classified as a firearm.

[cxwq]

That's just part of the code, as reported in their FAQ.

As I've stated many times, the full ATF definition of a silencer does not require that it is made for a firearm, but that it could be used on a firearm. Unfortunately, that is rather open to interpretation by local law enforcement.

[taita cakes]

The fact is that the pvc would be good for about one shot. Wouldn't it?

You'd expect PVC to melt pretty fast under all that heat and pressure.

Either way, i don't nerf in public, so it's not like i can get caught with a silencer. Not that i'm condoning it. I'm just glad we don't have little miss morals over here, as well as NHQ. *phew*.

Any chance of getting some microphone recordings of these silenced shots? Compared to unsilenced?

EDIT: Congrats on the 1900 posts cx.

Edited by taita_cakes, 07 July 2004 - 04:18 AM.

[okto]

i dont care about the legality of it
and thanks for the dollar.

so, decelerating air...ive been musing. as the dart leaves the muzzle, the air compressed in the barrel expands rapidly outward, as the tail end of the dart will prevent the majority of it from going forward. probably some turbulence from the compressed air in the dart (i hollow mine out nerf-style), but i think that can be mostly ignored. so venting it outward right at the muzzle should reduce the noise by the greatest factor, rather than setting up a pressure wave down the silencer tube. i drilled as many more holes as i think the CPVC can withstand structurally right at the muzzle, but it still doesnt seem to be having a great effect. i wonder if a stepped series of progressively larger tubes, like so:

        vents
       ___  __  _____________________
       |_____________               |PVC tube 2
______|            |PVC tube 1     |
       |            |               |
       | muzzle     |               |
       |            |               |
______|            |               |
       |____________|               |
       |__  __  ____________________|

etc, so that the inner PVC tube's "muzzle" has room around and behind it for air to expand into and be vented out laterally, et caetera ad infinitum. wrap the whole thing in felt or whatever to muffle it even more.
thoughts?

Edited by okto, 07 July 2004 - 04:30 PM.

[polarthunder]

Honestly, I doubt anyone will care if you have a silencer on your nerf gun. Many airsofters (myselft inluded) have "silencers". They look like silencers, but do very little, if anything, in silencing.

[okto]

i'll care. i dont want it to impress (in fact in use, i dont even want the gun or myself to be seen), i want to make it quieter, as near silent as possible.
how many of these airsoft silencer lookalikes are actually designed to dissipate muzzle air? ive seen them too, and its usually just a piece of PVC fitted over the barrel. that actually makes the muzzle blast louder. it confines the air to the cylinder formed by the inside of the PVC, and sets up a pressure wave down the tube, pushing the unmoving air in the tube ahead of it, and usually inducing some harmonic resonance in the tube, similarly to a flute only higher pressure and not sustained.

that wasnt supposed to be a flame, hopefully nobody get their toes stepped on. if so, apologies in advance.

[GeneralPrimevil]

Good thing you put that last part in on the bottom, cause the rest was BS.

Anyhow,

taita_cakes said

Maybe he should try hundreds of minute holes with the smallest drill bit he's got, and then not wrap it with foam insulation/layers.

Definetly good idea. I stuck a muzzle brake (very similar to what was mentioned, only bigger holes [3/8"], and three slits mounted in a triangular fasion, all of which were 1/4" by 1/2") on the end of my supersoaker barrel, took about half the decibels off. Then again, the barrel is 15/32" leading to 17/32", followed by a connector that is 5/8", which finally leads to the 3/4" PVC ported muzzle brake, which means air may have escaped somewhere in there, although I highly doubt it cause my darts expand to the diameter of the barrel. By the way, those were all the ID of the things mentioned.

[okto]

how...was it bs?

after more experimentation the answer is BIG hole(s) right at the muzzle, with some dissipative material covering them. this has the unforeseen pleasant side effect of increasing my RoF by allowing my to insert a new dart without removing the entire silencer. this reduces the muzzle noise to more of a soft "thwip", and has made it apparent that my job of silencing the internals wasn't as well done as i thought--most of the noise was actually the piston and spring, the muzzle noise was just the most obvious noise.

[taita cakes]

General Primape said

Anyhow,

taita_cakes said

Maybe he should try hundreds of minute holes with the smallest drill bit he's got, and then not wrap it with foam insulation/layers.

Definetly good idea. I stuck a muzzle brake (very similar to what was mentioned, only bigger holes [3/8"], and three slits mounted in a triangular fasion, all of which were 1/4" by 1/2") on the end of my supersoaker barrel, took about half the decibels off. Then again, the barrel is 15/32" leading to 17/32", followed by a connector that is 5/8", which finally leads to the 3/4" PVC ported muzzle brake, which means air may have escaped somewhere in there, although I highly doubt it cause my darts expand to the diameter of the barrel. By the way, those were all the ID of the things mentioned.

Thank you, and thank you for some exact measurements. But i think a thin layer of felt/foam/material would be required to control the speed of the air dissepating. And anyway, maybe your gun, has infact, reached its most silent form *DUN-DUN-DUHHHNNNN*

[okto]

Quote

maybe your gun, has infact, reached its most silent form *DUN-DUN-DUHHHNNNN*

nooooo! it needs to be quieter!

anyway, as it stands i have a 6" length of 1/2" CPVC, with a 2.5" x 3/4" slot cut in right at the muzzle, and a piece of pipe insulation over the lot. from holding the gun and firing it, all i her is spring noise, no pop.
so next step is i'm replacing the piston and cocking lever with something stronger, to minimize breakage (and allow me to adopt a design more suited to silencing), reinforce the spring retention wall, get a bigger spring, and rebarrel.

so basically, the totally unnecessary portion is done, and now i only have to do all the important bits

[taita cakes]

Marvellous. Simply, Marvellous!

This is sounding like an extra cool gun. I'm going on a quest to find a LNL now. Then, let the fun begin.